.box li:nth-child(3) {
   display: none; 
}
@media (min-width:768px) {
    .box li:nth-child(3) {
        display: none; 
     }
    }
    @media (min-width:992px) {
        .box li:nth-child(3) {
            display: none; 
         }
        }
        @media (min-width:1200px) {
            .box li:nth-child(3) {
                display: none; 
             }
            }
            